Tube for receiving pasty substances



Nov. 15, 1 1-1. E. .1. FUHRMANN 3,285,473

TUBE FOR RECEIVING PASTY SUBSTANCES Filed Nov. 2, 1964 H1 Ill Fig.7 Fig)I I Fig.3

INVENTOR. Hen/K10! psrJSmw lm/M United States Patent 3,285 473 TUBE FORRECEIVING PASTY SUBSTANCES Heinrich Ernst Johann Fuhrmann, EschersheimerLandstrasse 68, Frankfurt am Main, Germany Filed Nov. 2, 1964, Ser. No.408,067 6 Claims. (Cl. 222-107) The present invention relates to a tubefor receiving pasty substances, such as greases, color pastes,ointments, and the like. More specifically, this invention is directedto a tube of the folded wall or bellows type which is emptied either byapplication of atmospheric pressure in cooperation with a partial vacuumwhich becomes effectice at the tube outlet opening, or by a gaseousmedium under pressure, such as compressed air.

Very frequently, tubes of the above-noted type cannot properly beemptied when they are used in emptying devices in which the contents ofthe tube are not squeezed out by some mechanical means, such as pistonsor the like. By proper emptying is meant here that the tube can becompletely emptied and that during the emptying process, which isinitiated arid continued in response to a partial vacuum at the tubeoutlet, no constrictions are formed in the tube which would impair theproper emptying of the tube. In conventional tubes of the folded wall orbellows type such constrictions may occur, if pressure is applied to theouter tube surfaces of a partly filled tube. In such a case the tubeinterior adjacent the tube outlet would be reduced in area, since thesubstance with which the tube is filled flows off first from that regionof the tube which is adjacent the outlet opening. As a result, thesubstance in the narrowed areas of the tube cannot flow off any longer.As the emptying process continues, the folds of the tube progressivelyapproach each other, until they lie closely side by side. Since thewalls of the tube have a certain thickness, the wall thicknesses of thefolds add up so that the tube will have a certain height even when itsfolds lie closely side by side. Thus, if it is assumed that there aretwenty folds and that the Wall thickness is about 0.04 in. then the tubestill would have a height of about 1.6 in., when collapsed, That is tosay, even when the tube folds would lie closely side by side, therewould be left a cylindrical interior space which would be enclosed bythe collapsed folds and could not be emptied anymore.

Accordingly, it is a primary object of this invention to provide a tubeof the folded wall type which can be properly and completely emptiedwithout the aid of me-. chanical means such as pistons or the like.

Another object of the invention is to provide a tube in which noconstrictions will occur, as the tube is emptied by applying underpressure a gaseous medium to its surfaces.

Still another object of the invention is to provide a tube in which thethickness of the tube walls at the end remote from the tube outletopening is so selected that this portion of the tube can be turnedupside down into the cylindrioal interior space of the tube which isleft over after the folds are collapsed.

The tube of the invention has ring-shaped or helical folds and exhibitsa radial resistance to deformation, which progressively increases in thedirection of the tube outlet opening. This radially effective resistanceto deformation is brought about by either progressively increasing thethickness of the tube walls in the direction of the tube outlet openingor by progressively reducing the spacing of adjacent folds in thedirection of the tube outlet opening or by a combination of both.

Thus the tube of the invention has at its outlet end a larger walltln'ckness or more closely spaced folds or both so that this tubeportion is particularly resistant to 3,285,473 Patented Nov. 15, 1966ice external pressure, thereby preventing any early formation ofconstrictions.

On the other hand, the tube bottom and the adjacent portions of the tubeWalls are less resistant to deformation, because the wall thicknessprogressively decreases in the direction of the tube bottom, or thespacing of adjacent folds becomes progressively larger or both, so thatthe less resistant bottom portion of the tube can be turned upside downinto the above-noted remaining cylindrical interior space of the tube atthe end of the emptying operation.

Further features and advantages of the tube of the invention will becomeapparent from the following detailed description, when read inconjunction with the drawings, in which several embodiments of theinvention are illustrated.

In the drawings FIGURE 1 is a cross-sectional view of a tube emptyingdevice with an inserted tube of the invention, the lefthand tube portionbeing shown provided with a folded wall of varying thickness and theright-hand tube portion being shown provided with differently spacedfolds;

FIGURE 2 is a cross-sectional view of the device of FIG. 1 with a partlyemptied tube, and 1 FIGURE 3 shows an emptying device with a partlyemptied tube and means for preventing expansion of the emptied tube.

Referring now more particularly to FIG. 1, there is shown theconventional emptying device which comprises substantially the followingparts: An enclosure 1 having an opening 2 through which a collapsidbleor folding tube 3 may be inserted. Enclosure 1 is made from rigidmaterial and supported from a hollow elongated portion 4 whichaccommodates a low-pressure cylinder 5 and a high-pressure cylinder 8which can be fitted over a stationary piston and sealed by a ball valvemember 7. Upon forcing the emptying device with its outlet end 9 over alubrication nipple (not shown), cylinder 8 is caused to slip over pistonmember 6. Upon exerting no pressure on the device in this position anylonger, a spring 10 urges cylinder 8 away from piston member 6, therebycausing negative pressures to be generated in cylinders 5 and 8. Thesenegative pressures have a cumulative effect on the tube opening 11 sothat the atmospheric pressure may become effective through aperture 2thereby impinging upon the entire tube surface area. This causes thegrease or any other substance with which thetube may be loaded, to flowfrom tube region 12 adjacent tube opening 11 through the latter intocylinder 5. Upon application of the next stroke this portion of the tubecontents is forced by piston 6 into the lubrication nipple. Of course itis also possible to provide for instance a pressure line through which agaseous medium may enter enclosure 1 through opening 2. If the walls oftube 3 had a uniform thickness throughout, or, if the folds were ofequal size, then it might be possible that the tube is radially narrowedor constricted in outlet region 12 from which the grease would flow offfirst. As a result, the supply of grease from the remaining tube portion13 would be impeded. To eliminate this disadvantage, tube walls 14 arerelatively thick adjacent the outlet region, whence they graduallydecrease in thickness in the direction of tube bottom 15, as shown inFIG. 1 at the left. Alternatively, the folds in the tube walls of thelower or outlet zone of the tube may be spaced more closely side by sidethan the folds adjacent the bottom of the tube. Either arrangement hasthe advantage of providing a maximum radial resistance to deformationsof the lower or outlet portion of the tube, Naturally, the two wallsarrangements can be combined, if desired, as shown in FIG. 3.

FIG. 2 shows tube 3 almost emptied. That is to say,

the tube has been forced together so that its folds are spaced closelyside by side. In this state, a remaining cylindrical space 16 isenclosed by the folded walls of the contracted tube. Normally, space 16can hardly, if at all, be emptied. However, since the tube walls arethinnest in tube region 15, the tube bottom and part of the adjacentfolds may be urged into the remaining cylindrical space 16, as indicatedby the dash-dotted line in FIG. 2, thereby squeezing any remaininggrease out of space 16.

To prevent tube 3 from being unfolded or expanded in enclosure 1 afterit is empty, as would be the case, if for instance ball valve member 7were leaky, the embodiment of the tube shown in FIG. 3 is used incombination with a so-called follower piston 17. This piston must havean aperture 18 to permit the tube to be completely emptied, as describedin conjunction with FIG. 2. As tube 3 contracts, piston 17 follows tubebottom 15 steadily. Small springloaded balls 19 are provided inenclosure 1 which are urged against the walls of enclosure 1 therebyproducing a clamping effect which prevents piston 17 from returning toits starting position. It should be understood that also other suitablemeans may be used as clamping elements,'it being only necessary thatsuch elements provide the desired clamping effect. The piston may be ofthe same material as the tube. Such a material may be a polymer plasticmaterial such as plasticized polyvinyl chloride, polyethylene, etc. Inoutlet zone 12 the folded walls of the tube are about .010 to .020 in.thick, whereas the thickness of tube bottom 15 and of the tube wallsadjacent bottom 15 may range from about .004 to about .008 in.

While the present invention has been described hereinbefore inconnection with lubricating sets which are loaded with lubricant-filledcartridges or tubes, it will be understood that this invention may bepractised in all cases where cartridges or tubes filled with pastysubstances have to be inserted into emptying devices. Accordingly, thescope of this invention is to be governed by the language of thefollowing claims construed in the light of the foregoing description ofthis invention.

What is claimed and desired to secure by Letters Patent is:

1. A tube having folded wall surfaces, comprising a closed bottomportion, a top portion having an outlet opening therein, and a tubularintermediate portion extending between said bottom portion and said topportion, said intermediate portion having folds and deformationresistantmeans, the resistance offered by said deformation-resistant means toradial deformation by pressure being at its maximum adjacent said topportion and at its minimum adjacent said bottom portion, said bottom andtop portions as well as said folded intermediate portion being walls,the walls forming said bottom portion 4 and the bottom end of saidfolded intermediate portion being thinner than the walls forming the topend of said folded intermediate portion, the thinner walls of saidbottom portion and said bottom end of said folded intermediate portionforming a tube portion extending upside down into the interior of saidtube upon application of pressure on said thinner walls.

2. The tube according to claim 1 wherein the walls of said foldedintermediate portion are thick adjacent said top portion and areprogressively reduced in thickness in the direction of said bottomportion such that said bottom portion is at least as thin as said bottomend of said folded intermediate portion.

3. The tube according to claim 2 wherein the wall thickness of said topend of said folded intermediate portion is about .010 to about .020 in.and the wall thickness of said bottom end of said intermediate portionis about .004 to about .008 in.

4. The tube according to claim 1 wherein adjacent folds of saidintermediate portion are spaced more closely at said top end than atsaid bottom end of said intermediate portion, the arrangement being suchthat the spacing of said adjacent folds progressively increases in thedirection of said bottom end.

5. The tube according to claim 1 wherein said resistances to deformationare effected by a combination of the wall thickness of said intermediateportion with the folds of said intermediate portion, the wall thicknessof said intermediate portion progressively decreasing from said top endin the direction of said bottom end, adja cent ones of said folds beingspaced more closely at said top end than at said bottom end, thearrangement being such that the spacing of adjacent ones of said foldsprogressively increases in the direction of said bottom end throughoutthe length of said intermediate portion.

6. The tube according to claim 5 wherein the wall thickness of said topend of said folded intermediate portion is about .010 to about .020 in.and the wall thickness of said bottom end of said intermediate portionis about .004 to about .008 in.

References Cited by the Examiner FOREIGN PATENTS 1/1938 Great Britain.4/ 1964 Great Britain.

OTHER REFERENCES German application 1,118,399, November 1961.

1. A TUBE HAVING FOLDED WALL SURFACES, COMPRISING A CLOSED BOTTOMPORTION, A TOP PORTION HAVING AN OUTLET OPENING THEREIN, AND A TUBULARINTERMEDIATE PORTION EXTENDING BETWEEN SAID BOTTOM PORTION AND SAID TOPPORTION, SAID INTERMEDIATE PORTION HAVING FOLDS AND DEFORMATIONRESISTANTMEANS, THE RESISTANCE OFFERED BY SAID DEFORMATION-RESISTANT MEANS TORADIAL DEFORMATION BY PRESSURE BEING AT ITS MAXIMUM ADJACENT SAID TOPPORTION AND AT ITS MINIMUM ADJACENT SAID BOTTOM PORTION, SAID BOTTOM ANDTOP PORTIONS AS WELL AS SAID FOLDED INTERMEDIATE PORTION BEING WALLS,THE WALLS FORMING SAID BOTTOM PORTION AND THE BOTTOM END OF SAID FOLDEDINTERMEDIATE PORTION BEING THINNER THAN THE WALLS FORMING THE TOP END OFSAID FOLDED INTERMEDIATE PORTION, THE THINNER WALLS OF SAID BOTTOMPORTION AND SAID BOTTOM END OF SAID FOLDED INTERMEDIATE PORTION FORMINGA TUBE PORTION EXTENDING UPSIDE DOWN INTO THE INTERIOR OF SAID TUBE UPONAPPLICATION OF PRESSURE ON SAID THINNER WALLS.